Collaboration is an essential part of any organisation. Working in a team increases productivity, shares knowledge and stimulates creativity. It also provides a critical environment for the development of ideas and services. With the growth of cheap international communication systems, such as the network of computers and fibre-optic cabling that comprises the Internet, organisations can collaborate on a global scale across different continents and time-zones. Even at a local level, flexible working practices and the near ubiquitous availability of wireless communication systems, mean that team members may collaborate at the same time in diverse geographical locations or at different times in the same office. Such collaboration may also involve a number of users operating on a number of different network devices.
Most forms of modern collaboration involve the editing of electronic files. These files may comprise, amongst others, word processing documents, spreadsheets, databases, multimedia presentations, audio and video content, computer-program code or proprietary file types. A number of approaches have been proposed in the art to enable collaboration on such files.
A first approach uses a single central repository to maintain a master version of a given file or document. Individual users retrieve (or ‘check out’) the latest version from the repository and later save (or ‘commit’) a new copy, including any changes they have made, back to the repository. Well known examples of such arrangements include the Concurrent Versions System (CVS) developed by Richard Grune and Subversion (SVN) developed by CollabNet Incorporated, both of which provide an open source solution to the problem of managing different versions of computer-program code during application development. In certain cases the repository may be provided by a server connected to the Internet. In this case a plurality of client devices may access the repository as an online service to “checkout” and “commit” documents (for example, Microsoft Office Live supplied by Microsoft Corporation).
A similar approach is set out in WO/2005 114467 A2, wherein a remote computer system is provided. The remote computer system acts as a server to a number of workstations and stores a document to be edited as a plurality of linked character objects. Through communication between a workstation and the remote computer system the centrally-stored document may be updated. However, this system suffers from the usual drawbacks associated with a server-centric system as discussed further below.
Document management solutions of this type generally encounter difficulties when more than one user simultaneously edits a document. In such circumstances there may be ‘clashes’ between the edits made by each user: for example, users A and B check out version 1 of a given document; user A then commits version 1.1 with changes; and user B subsequently commits version 1.2 with changes. At this stage, version 1.2 lacks the changes made by user A.
Merge tools have been proposed that work to merge the changes made in different versions, e.g. versions 1.1 and 1.2 above, such that a consolidated version of the document can be produced. These mechanisms are usually associated with the repository approach, but may also be found in freestanding software such as Microsoft Word, also supplied by Microsoft Corporation. The use of merge tools does not necessarily offer sufficient consistency in all circumstances. For example, if the edits made by users A and B are mutually exclusive (for instance, user A deletes a paragraph while user B adds detail to it) there is the potential for simple merge tools to produce incoherent results.
An alternative approach has been suggested whereby all users edit online a document stored on a central server. In such systems, the document is not checked out for local editing. Instead, each user sets up a connection with the central server and any changes are made directly to a master version of the document stored on the server. An example of a technique of this type is Google Documents, provided by Google Incorporated. However, in order to use systems such as these, users must be online in order to access the centrally stored document. Additionally, users must also be online to edit the document. This may cause problems in situations where the connection to the server is prone to interruption, for example when exchanging data from a moving vehicle using wide area cellular telephone networks.
Another alternative approach to the management of a single document by multiple users is desktop sharing. According to this approach, a first user stores a document and is able to allow remote access to their computer by one or more further users, allowing the further users to temporarily control the application that is used to edit the document. This is similar to the central server approach discussed above, with the difference being that a particular user's machine is used as the server. Examples of this approach include Cisco Webex, provided by Cisco Systems Incorporated, and Microsoft SharedView, provided by Microsoft Corporation. This approach, however, does not allow simultaneous editing of the document by more than one user.
Microsoft Corporation also describe a method, system and apparatus for collaboration in EP 1 589 722 A1. This publication describes a variation of their “OneNote” application. A shared note-taking session is set up between users using a shared session application program interface (API). In this shared session, page synchronisation objects are used to synchronise changes applied to respective pages of a note-taking document. A synchronisation token is required to make changes to a page synchronisation object. While the described method, system and apparatus do address certain problems in real-time collaboration, they are nevertheless inflexible and do not allow for free collaboration. For example, the need for a shared session restricts international collaboration and the need for a synchronisation token generates a certain set of problems that are well-documented in the field of ring network topologies.
A further approach that may be implemented on a common network is to adapt existing message passing software operating on the network. For example, one could write a custom formula for each cell in a spreadsheet such as Microsoft Excel, provided by Microsoft Corporation, that invokes an application such as Tibco Rendezvous, provided by Tibco Software Incorporated to publish a piece of information over the network infrastructure. The disadvantages of this approach are two-fold: firstly, there is a lack of control over the publication of changes, such information is simply placed onto the network for retrieval; and secondly, the author has to explicitly state what information within the document is to be shared and specifically configure the document itself (i.e. has to manually configure each cell) to share such information, not only does this create a much larger document, it requires each document to be customised in a manner that takes time and specialist knowledge.
US2004/0088646 A1 extends the message passing method by passing a mobile agent between nodes, i.e. between computers. The mobile agent may be a Java class. The mobile agent, once it has arrived at a node, may check version information so as to lock a document and send the latest version of a document to other nodes. However, this approach not only suffers the disadvantages of message passing but also those of document locking and sharing as discussed above and below. The mobile agent also may present a security risk.
The limitations on the existing document management techniques outlined above mean that users commonly resort to simply serially distributing a document between collaborators. Often this is achieved by attaching the document to an electronic mail message (“email”) addressed to an appropriate user. For example, user A creates version 1.0 and transmits it to user B, who creates version 1.1 and transmits it to user C, and so on. The limitations of this approach are readily apparent: not only is simultaneous editing of the document by more than one user impossible, but users are unable to contribute until it is their turn. Furthermore, the common use of email produces additional problems such as a lack of security and limits on transmitted file size.
Hence, there is a requirement in the art to provide a method and/or a system to enable users to collaborate on a file or document without the problems described above. Such a solution should preferably be easy to use, should enable real-time editing by multiple users and should facilitate, rather than constrain, the collaboration process.